python - Google API quickstart.py error KeyError: '_module'

Question

Using Gmail API. My client secret file is downloaded and working for Ruby. When I try the quickstart.py (python) version I get this error

File "quickstart.py", line 70, in <module>
    main()
  File "quickstart.py", line 55, in main
    credentials = get_credentials()
  File "quickstart.py", line 38, in get_credentials
    credentials = store.get()
  File "/Library/Python/2.7/site-packages/oauth2client/client.py", line 374, in get
    return self.locked_get()
  File "/Library/Python/2.7/site-packages/oauth2client/file.py", line 79, in locked_get
    credentials = Credentials.new_from_json(content)
  File "/Library/Python/2.7/site-packages/oauth2client/client.py", line 281, in new_from_json
    module = data['_module']
KeyError: '_module'

I have not changed the file at all, just added the client_secret.json to that working directory and also install the google-api-python-client. My python code came from here: https://developers.google.com/gmail/api/quickstart/python

Answer 1

oauth2client is trying to load credentials from a json file with an incorrect structure.

Maybe the Ruby client uses a different file format but I'd be surprised. Are you sure you didn't save client_secret.json as ~/.credentials/gmail-quickstart.json accidentally?

Regardless, removing ~/.credentials/gmail-quickstart.json and re-authenticating will generate a new credentials file with the correct structure.